Process of manufacturing and tempering steel



MARTIN FRANCIS COOMES AND ARUNAH VVATERMAN HYDE, OF LOUIS- VILLE, KENTUCKY.

PROCESS OF MANUFACTURING AND TEMPERING STEEL.

SPECIFICATION forming part of Letters Patent No. 440,139, dated November 11, 1890.

Application filed February 7, 1890. Serial No. 339,589. (No specimens.)

To all whom it may concern.-

Be it known that we, MARTIN FRANCIS OooMEs and ARUNAH WATERMAN HYDE, citizens of the United States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented certain new and useful Improvements in the Process of Manufacturing Steel; and we do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of our invention is to obtain a new and cheap tempering-bath and method of carburizing malleable cast-iron and steel which is low in carbon, and thereby convert them into a steel which is high in carbon. We attain this object by making a triple-sat- 11 rated solution in Water of chloride of sodium, chloride of ammonium, and sugar. Sirup, molasses, honey, or any similar saccharine substanceis the equivalent of the sugar. Into this bath we place the metal to be carburized, raised to a white heat, and allow it to remain while cooling. The heat of the metal decomposes t-he bath, setting the carbon free, which is absorbed by and chemically unites with the metal.

The method of making the bath which we prefer is as follows: First, we make a saturated solution of chloride of sodium and water;

second, to said solution we add as much sugar as it will dissolve; and, third, to said double-saturated solution we add chloride of ammonium until it will hold no more. This triple-saturated solution is very dense, and possesses valuable properties as a tempering-bath. It is used for tempering in the ordinary manner, the metal, raised to a cherryred or a dull cherry-red heat,being placed in the bath and allowed to remain until the desired temper is obtained.

Having thus fully described our invention, what we claim, and desire to secure by Letters Patent, is-

1. In the manufacture of steel, the process of carburizing malleable cast-iron and lowcarbon steel, which consist-s in placing the metal raised to a white heatin a bath composed of Water, a sugar, chloride of sodium, and chloride of ammonium, substantially as described.

2. As a tempering and carburizing bath, 

